In the commercial cooking environment there are generally two types of steam cooking ovens used. In the typical countertop “atmospheric” steamer the bottom of cooking cavity itself includes a water volume from which steam is produced (i.e., steam is produced directly within the cooking cavity). The cooking cavity has an outlet opening such that excess steam can exit the cavity, where it is delivered up a vent stack. In the typical larger, higher capacity steam oven a separate steam generator is used and a steam feed line runs from the steam generator to the steam cavity. The steam cavity includes a drain outlet opening through which condensed water is delivered to a drain at the site of installation. The steam cavity does not have an associated vent stack, so any excess steam within the cavity is also delivered along the drain path. Generally, this arrangement requires the use of some type of tempering along the drain path so as to assure that the maximum permitted temperature according to applicable code is not exceeded. Delivering steam down the drain wastes energy, due to both the loss of steam and the tempering that must be performed to regulate the drain temperature.
It would be desirable to provide a steam cooking oven of the type including a steam generator external of the cooking cavity, but having improved efficiency.